Key-gage.



J. C. ROSS.

KEY GAGE.

APPLICATION FILED MAY SI, I9I6. I 1&2279492 Patented May 22, 1917.

j@ J ZF/gc Z frau e RO 7".'

@fila I JOHN COWAN ROSS, OF BOSTON, MASSACHUSETTS.

KEY-GAGE.

Specification of Letters Patent.

vlPatented May 22, 191W?.

Application filed May 31, 1916. Serial No. 100,849.

To all whom it may concern:

Be it known that I, Jol-IN CowAN Ross, citizen of the United States, andresident of Boston, in the county of Suolk and State of Massachusetts,have invented new and useful Improvements in Key-Gages, of which thefollowing is a specification.

This invention relates to key gages of the character shown in LettersPatent No.

lo 1,175,819, granted to me March 14, 1916, and in my application forLetters Patent of the United States led December 24, 1915,' Serial No.68,524. In key gages of the type shown in said patent and patentapplication,

if'the key is not held firmly and accurately in place by hand in the keyway, inaccuracies and errors will arise in the use of the key gage. Whenthe key gage is held in place by hand it has been found diiiicultwithout 2O extreme care and some measure of skill to manipulate the gagewithout danger of displacing the key slightly from its accurate positionin the key way. One of the objects of the present invention is toprovide means in proximity to the entrance opening of the key wayadapted to engage the shoulder of a key in the key way and hold itfirmly in place. It is also an object of the invention to provide meansfor holding the rotary barrel and the adjustable key stop described -inmy said patent application in any of their several positions ofadjustment, and also to accomplish the further purpose of holding thekey in place in the key way and holdingl the barrel and adjustable keystop in position by means of the same latch. These and other featureswill hereinafter be more fully described and particularly lpointed outin the claims.

In the accompanying drawings which illustrate the preferred embodimentof my invention,

Figure 1 is a side elevation of a key gage containing the invention;

Fig. 2 is an end elevation of said key gage;

Fig. 3 is a side elevation partly in vertical section through the latchand latch carrying finger showing a key in the key gage; and

Fig. 4 is an end view similar to Fig. 2 but showing in cross section akey in the key way.

A represents the frame or housing of the gage, having a key way a whichopens through one end of the frame. A sight aperture a is provided inthe side of the frame at the side of the key way to expose to view thenotched edge of the key and the ends of the gage pins c which aremovably mounted in the frame A.

B is a barrel or cylinder mounted to turn within the frame to vary thedistances between the several gage pins, as explained in my said formerapplication. The rotary barrel B is located alongside of the key way andextends through the end of the frame at one side of the key way opening.The end of the barrel is provided with a series of notches o, which arepreferably of varying depths, and constitute key stops to engage theshoulder 7c of the key K and determine the penetration of the key intothe key way. Adjustable guide screws d, d, one on each side of the gage,are provided to bear against the sides of the key within the usualgrooves which run lengthwise of the key to aid in holding the key inposition.

The parts thus far described may be sub stantially the same as thecorresponding parts described more in detail in my said former patentand patent application.

At the end of the frame A through which the key way opens and from whichthe end of barrel B projects, there is iiXed a latchcarrying finger E,which projects over the end of the barrel and over the rotary key stop.The finger E is secured to the frame by means of a screw c which passesthrough the top of the frame A into the top of the latch-carryingfinger. rIhe finger E is provided with a longitudinal bore containing alatch consisting of the rod ,f and the head z. Said latch is yieldinglypressed forward by a coil spring g lodged in said bore behind the rod f.l The head la, of the latch is preferably tapered on all four sides, ormade in substantially pyramidal form'so as to provide a bevel on allfour sides for the purpose hereinafter described. The latch normallyprojects into engagement with one of the series of notches b, whichconstitute the key stops, and forms means for yieldingly holding therotary barrel B and the adjustable key stop in any one of its severaladjusted positions. rIhe latch is also in proximity to one end of thekey way opening in position to engage the shoulder 7c of the key, andthe bevel surfaces on the inner and outer sides of the head 7L, whenengaged by the shoulder k of the key, permit the latch to yield bothwhen the key is being thrust into the key way and when it is beingpulled out of the key Way. The latch-carrying finger E, Which projectsacross the ace of the adjustable key stop at the end of the barrel B,serves both as a housing and support for the latch, and also to preventthe dislodgment of the barrel from the iframe.

"With this construction When the key is inserted in the key Way, in theposition shown in Fig. 8, the latch Will engage the outer side of theshoulder 7c and hold the key in its proper position so that both handsof the operator are free for the manipulation of the gage pins and otherparts. Moreover. whether the key is in the gage or not said latch willalso engage the notches on the end of the barrel constituting the keystops, thereby holding the barrel and key stops in the desired positionof adjustment; and when the key i's out of the gage the bevel surfacesat the sides oi" the latchwwill permit the latch to yield as the barreland notched key stop are rotated, and to snap into the successivenotches Z) thereby aiding in bringing the latter into correct registryWith the key Way.

I claim:

l. A key gage of the character described comprising a frame having akey-Way, and a latch carried by the frame in proximity to one end of thekey-Way opening, adapted to engage the shoulder of a key in the key-Way.

2. A key gage of the character described comprising a frame having akey-Way, a

latch carried by the frame in proximity to one end of the key-Wayopening, adapted to engage the shoulder of a key in the key- Way, and aspring normally pressing said latch forward, said latch being beveled onboth its outer side and its inner side to yield to the movement of thekey in either direction.

3. A key gage of the character described comprising a frame having akey-Way, an adjustable key stop adapted to determine the penetration ofthe key intothe key-Way, and a latch carried by the :trame adaptedyieldingly to hold said adjustable key stop in any one of .its severaladjusted positions.

4. A key gage of the character described comprising a frame having akey-Way, an adju-stable key-stop Yadapted to determine the penetrationof the key into the key-Way, and a latch carried by the frame inproximity to one end of the key-Way opening, adapted both to engage theyshoulder of a key in the keyuvay and to hold said adjustable key-stopin any one of its several adjusted positions.

5. A key gage of the character described comprising a frame having akey-Way, a rotary barrel at one side of the key-Way adapted to adjustgage pins, and a latch carried by the frame adapted yieldingly to holdsaid barrel in any one of its several adjusted positions.

6. A key gage of the character described comprising a frame having akey-\vay, a rotary barrel at one side of the key-Way adapted to adjustgage pins, and a latch carried by the iframe in proximity to one end ofthe key-Way opening, adapted both to engage the shoulder of a key in thekey- Way and to hold said barrel in any one of its several adjustedpositions.

7. A key gage of the character described comprising a frame having akey-Way, a rotary barrel at .one side of the key-Way and extendingthrough the end of the frame at one side of the key-'Way opening, alatchcarrying finger lixed to the Jframe and projectingover the end ofthe barrel, and a latch on said iinger adapted to hold said barrel inany one of its several adjusted positions.

8. A key gage of the character described comprising a frame having akey-Way, a rotary barrel at one side of the key-Way and extendingthrough the end of the frame at one side of the key-Way opening, alatchcarrying inger fixed to the iframe and projecting over the end ofthe barrel, and a latch on said finger adapted both to engage theshoulder of a key in the key-Way and to hold said barrel in any one ofits several adjusted positions.

9. A key gage of the character described comprising a frame having akey-Way, a rotary key stop at one side of the key-Way opening, having aseries of notches adapted severally to determine the penetration of akey into the key-Way, latch-carrying finger fixed to the frame andprojecting over the rotary key-stop, and a latch on said iinger adaptedboth to engage the shoulder of a key in the keyavay and to engage saidnotches and hold the rotary key stop in adjusted position. f

Signed by me at Boston, Massachusetts, this 26th day of May, 1916.

JOHN CGWAN' ROSS.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents,

Washington, I). C.

